太原市24所中小学校被命名为“太原市防震减灾科普教育园地示范学校”

强化中小学校防震减灾科普教育园地建设，是开展防震减灾科普宣传的有效途径。2006年12月20日，经太原市教育局和太原市地震局审核验收，太原市十五中、太原市三十六中、迎泽区桃园小学、杏花岭区解放路小学、阳曲县新阳街小学、古交市第一小学等24所中小学校，被命名为“太原市防震减灾科普教育园地示范学校”。     

太原区域地质构造及地震活动特点

本文利用地质和地震资料分析了太原市盆地区的构造特点,根据新生界厚度、微断块结构特点,提出太原市田庄断层以北盆地区与晋中盆地在构造和地震活动性上均存在显著差异,然而同忻定盆地具有某种可能联系。建议对北北西向构造的作用进行深入研究。     

基于GIS的震害预测信息管理系统设计--以山西省太原市清徐县为例

依据《清徐县地震灾害损失预测》项目，以山西省太原市清徐县为例探讨了基于GIS的震害预测信息管理系统的设计方法，叙述了系统的设计原则和总体框架的设计思路以及空间数据库和属性数据库的构建框架，重点介绍了系统主要功能模块——生命线工程模块的设计内容。     

太原市减轻城市地震灾害规划通过专家评审

太原市减轻城市地震灾害规划评审会在山西省地震防灾协调组主持下于1991年9月11日至13日在太原市召开。省市有关领导参加了会议。参加会议的单位有60多个,代表80余人。会议邀请同行专家14人组成评审委员会对规划进行了评审。 太原市是建设部确定的全国52个重点抗震城市之一,地处山西地震带上。在我国大陆地区地震活动进入新的活跃期的今天,编制太原市减轻城市地震灾害规划,逐步提高城市综合抗震能力,最大限度地减轻城市地震灾害,确保社会主义建设的顺利进行,是完全必要的,非常及时的。     

陆内盆地与强震活动ht

1303年9月27日的山西洪洞8级地震发生于山西断陷盆地带中的临汾盆地，这是我国自有地震历史记载以来的第一次8级地震，也是一个在活动陆内盆地中发生的大地震. 2003年9月17~18日在山西太原市召开了1303年山西洪洞8级地震700周年暨陆内盆地与强震活动研讨会. 会上交流的论文讨论了我国不同地区发育的不同性质的陆内活动盆地，包括拉张构造区的地堑、半地堑张性盆地，挤压构造区的压陷盆地和前陆盆地及走滑构造带内的拉分盆地与强震活动的关系. 本文对这些问题作了简要的总结，本期刊登的论文是由部分会议论文组成的专辑.      

活动断裂地震变形与重大工程场地安全距离研究

在不考虑地表覆盖层的情况下，采用三维有限元方法计算了不同震级、不同断层活动方式以及不同断层倾角下断层上、下盘地表的地震位移及形变分布，通过设定的安全距离判定标准，研究了各种情况下工程场地距断层的安全距离。研究表明，活动断裂的安全距离应根据断裂性质、活动方式、活动强度、断裂上下盘等因素及工程设防要求共同确定。     

活断层的地质研究及其在工程安全性评价的意义

活断层是导致多种地质灾害，特别是地震、崩塌、滑坡、地表断错的重要根源，对工程设施具有重大的破坏作用。因此，活断层的研究就成为地震危险及工程安全性评价的重要内容。为确保工程安全，加强对工程活断层评价是人类战胜自然灾害的一个重要方面。本文着重讨论了三个问题（一）工程评价中的活断层含义：工程评价中的活断层是指晚更新世（１０万年）以来，特别是全新世（１万年）以来有过位移活动，且在未来工程使用期内仍有可能活动的断层，这类断层往往是沿袭先存断层面发生突然错动或缓慢蠕动使上覆第四纪新沉积物及其它地物标志发生相对位移。（二）活断层的地质研究包括（１）断层出露的位置、规模及其活动时代；（２）断层运动性质及活动方式；（３）断层几何配置；（４）断层滑动速率；（５）断层活动的分段性；（６）断层活动潜在地震能力的判定；（７）在未来一定时期内断层可能位错量的预测等７个方面。（三）活断层在工程安全性评价中的意义：随着我国国民经济建设的发展，大型工程设施将愈来愈多，如超高建筑，大型桥梁、隧道，大中型水库、核电站、高速公路、地下铁道、国际机场、重要广播、电视发射台、重要通讯枢纽，大型化工厂等。为确保工程的安全，活断层对工程的影响和破坏作用是     

1303年山西洪洞8级地震700周年暨陆内盆地与强震活动研讨会在太原召开

2003年9月17～21日,中国地震学会地震地质专业委员会、历史地震专业委员会以及山西省地震局在山西省太原市联合举办了“1303年山西洪洞8级地震700周年暨陆内盆地与强震活动研讨会”,来自全国各地的约100名专家、学者参加了会议。     

阳曲县防灾能力简析

本文从防震、水土保持、抗旱、防洪、生态调节、土地承载、社会经济等７个方面对山西省太原市阳曲县的防灾能力进行了分析，指出了灾害的隐患，提出了相应的防灾减灾措施。     

对2010年6月5日太原阳曲4.6级地震发震断裂的判定

2010年6月5日20时58分,山西省太原市阳曲县发生4.6级地震,太原附近城市震感明显。从这次地震的等震线图、余震分布特征、震源机制解入手,采用排查法,对震中区附近的主要活动断裂进行了逐个排查分析。最终判定交城断裂带北段的石岭关南缘断裂为本次地震的发震断裂。     

随机分布多导体圆柱目标散射的快速计算 及其成像模拟

用二维迭代方法快速地解析计算多导体圆柱目标的散射场,其中各圆柱目标自身的一次散射以各自中心为原点的柱面波函数叠加,匹配各圆柱表面的边界条件获得展开系数;各圆柱间的散射相互作用由坐标变换实现,具体体现在圆柱中心偏移产生的初始相位上.为考虑各个柱目标间的二次散射,将每个柱目标自身的一次散射看成另一柱目标的激励场,利用柱面波函数的加法定理和边界条件匹配来计算各柱目标间的二次散射贡献.类似的处理可获得三次或更高次的散射计算.与矩量法(MoM)的数值结果比较,验证了该方法的有效性,明显提高了后向散射的计算速度.对于随机生成的多个圆柱目标模型,解析计算一定频带f和360°方位角θ范围内均匀离散样点的后向散射场.为抑制数据截断产生的振铃效应,对频率向的散射数据用Hamming窗实现平滑过渡.为充分利用快速Fourier变换(FFT)的高效计算,对f－θ平面上的离散散射数据用二维的三次样条插值处理,得到X－Y平面的均匀离散数据.最后,用FFT方法快速实现逆合成孔径雷达(ISAR)成像模拟,很好地重构了各圆柱体目标的位置和大小尺寸.     

一种求解井间2.5维逆散射问题的迭代算法的研究

从二维非均匀介质中的声波方程出发,采用三维点源作为震源,提出了一种求解井间2.5维逆散射问题的迭代算法.其中,入射场与格林函数皆采用Maslov渐近理论予以计算,以避免非均匀介质中出现的焦散现象.数值模拟结果表明,本文提出的算法是有效的.     

Lanczos method for the solution of groundwater flow in discretely fractured porous media

One of the more advanced approaches for simulating groundwater flow in fractured porous media is the discrete-fracture approach. This approach is limited by the large computational overheads associated with traditional modeling methods. In this work, we apply the Lanczos reduction method to the modeling of groundwater flow in fractured porous media using the discrete-fracture approach. The Lanczos reduction method reduces a finite element equation system to a much smaller tridiagonal system of first-order differential equations. The reduced system can be solved by a standard tridiagonal algorithm with little computational effort. Because solving the reduced system is more efficient compared to solving the original system, the simulation of groundwater flow in discretely fractured media using the reduction method is very efficient. The proposed method is especially suitable for the problem of large-scale and long-term simulation. In this paper, we develop an iterative version of Lanczos algorithm, in which the preconditioned conjugate gradient solver based on ORTHOMIN acceleration is employed within the Lanczos reduction process. Additional efficiency for the Lanczos method is achieved by applying an eigenvalue shift technique. The “shift” method can improve the Lanczos system convergence, by requiring fewer modes to achieve the same level of accuracy over the unshifted case. The developed model is verified by comparison with dual-porosity approach. The efficiency and accuracy of the method are demonstrated on a field-scale problem and compared to the performance of classic time marching method using an iterative solver on the original system. In spite of the advances, more theoretical work needs to be carried out to determine the optimal value of the shift before computations are actually carried out.     

Iterative convergence of boundary-volume integral equation method

The boundary-volume integral equation numerical technique can be a powerful tool for piecewise heterogeneous media, but it is limited to small problems or low frequencies because of great computational cost. Therefore, a restarted GMRES method is applied to solve large-scale boundary-volume scattering problems in this paper to overcome the computational barrier. The iterative method is firstly applied to responses of dimensionless frequency to a semicircular alluvial valley filled with sediments, compared with the standard Gaussian elimination method. Then the method is tested by a heterogeneous multilayered model to show its applicability. Numerical experiments indicate that the preconditioned GMRES method can significantly improve computational efficiency especially for large Earth models and high frequencies, but with a faster convergence for the left diagonal preconditioning.     

Homotopy scattering series for seismic forward modelling with variable density and velocity

We have derived a convergent scattering series solution for the frequency-domain wave equation in acoustic media with variable density and velocity. The convergent scattering series solution is based on the homotopy analysis of a vectorial integral equation of the Lippmann–Schwinger type. By using the Green's function and partial integration, we have derived the vectorial integral equation of the Lippmann–Schwinger type that involves the pressure gradient field as well as the pressure field from the wave equation. The vectorial Lippmann–Schwinger equation can in principle be solved via matrix inversion, but the computational cost of matrix inversion scales like $N^3$, where $N$ is the number of grid blocks. The computational cost can be significantly reduced if one solves the vectorial Lippmann–Schwinger equation iteratively. A simple iterative solution is the Born series, but it is only convergent when the scattering potential is sufficiently small. In this study, we have used the so-called homotopy analysis method to derive an iterative solution for the vectorial Lippmann–Schwinger equation which can be made convergent even in strongly scattering media. The computational cost of our convergent scattering series scales as $N^2$. Our algorithm, which is based on the homotopy analysis method, involves a convergence control operator that we select using hierarchical matrices. We use a three-layer model and a resampled version of the SEG/EAGE salt model to show the performance of the developed convergent scattering series.     

Accelerating the T‐matrix approach to seismic full‐waveform inversion by domain decomposition

A seismic variant of the distorted Born iterative inversion method, which is commonly used in electromagnetic and acoustic (medical) imaging, has been recently developed on the basis of the T‐matrix approach of multiple scattering theory. The distorted Born iterative method is consistent with the Gauss–Newton method, but its implementation is different, and there are potentially significant computational advantages of using the T‐matrix approach in this context. It has been shown that the computational cost associated with the updating of the background medium Green functions after each iteration can be reduced via the use of various linearisation or quasi‐linearisation techniques. However, these techniques for reducing the computational cost may not work well in the presence of strong contrasts. To deal with this, we have now developed a domain decomposition method, which allows one to decompose the seismic velocity model into an arbitrary number of heterogeneous domains that can be treated separately and in parallel. The new domain decomposition method is based on the concept of a scattering‐path matrix, which is well known in solid‐state physics. If the seismic model consists of different domains that are well separated (e.g., different reservoirs within a sedimentary basin), then the scattering‐path matrix formulation can be used to derive approximations that are sufficiently accurate but far more speedy and much less memory demanding because they ignore the interaction between different domains. However, we show here that one can also use the scattering‐path matrix formulation to calculate the overall T‐matrix for a large model exactly without any approximations at a computational cost that is significantly smaller than the cost associated with an exact formal matrix inversion solution. This is because we have derived exact analytical results for the special case of two interacting domains and combined them with Strassen's formulas for fast recursive matrix inversion. To illustrate the fact that we have accelerated the T‐matrix approach to full‐waveform inversion by domain decomposition, we perform a series of numerical experiments based on synthetic data associated with a complex salt model and a simpler two‐dimensional model that can be naturally decomposed into separate upper and lower domains. If the domain decomposition method is combined with an additional layer of multi‐scale regularisation (based on spatial smoothing of the sensitivity matrix and the data residual vector along the receiver line) beyond standard sequential frequency inversion, then one apparently can also obtain stable inversion results in the absence of ultra‐low frequencies and reduced computation times.     

水平层状介质中基于DTA的三维电磁波逆散射快速模拟算法

为提高水平层状介质中三维电磁波散射和逆散射数值模拟的效率,在对角张量近似(DTA)的基础上根据不同回代方式得到了求解积分方程的DTA1和DTA2两种近似. 这两种近似可以作为计算积分方程稳定型双共轭梯度快速Fourier变换(BCGS-FFT)算法的初始猜测值和预条件因子,从而形成效率更高的混合DTA-BCGS算法. 散射实例说明了DTA2的高精度和混合DTA-BCGS算法尤其是混合DTA2-BCGS算法的高效率. 由于DTA2近似程度更高,将DTA2与变型Born迭代反演方法(DBIM)相结合形成了一种对三维异常体进行重构的快速电磁波逆散射技术. 文中的逆散射实例说明所开发的逆散射技术对重构水平层状介质中的任意三维异常体是非常有效的.     

井间地震射线层析成像

本文采用射线走时对井间介质的地震波速进行层析成像，反演出井间介质的异常分布和构造．作者用快速弯曲射线迫踪法求解初值问题，用两步法和插值逼近法结合求解两点问题，避免了复杂运算，提高了运算效率和精度．反问题的数值计算用ＬＳＱＲ法．为了求取速度任意分布、对比度大的较为复杂介质模型的槽确初至时，本文采用动态程序法。该法灵活不受地质界面条件约束，且对介质速度分布未加任何限制。本文给出了几个算例．文中层析成像试验结果表明，此种层析成像算法是成功和有效的。     

弹性波场数值模拟的隐式差分多重网格算法

为了得到稳定的弹 性波数值模拟,而不得不选择隐式差分方程;为了提高解的精度,又不得不增加节点数目, 但同时也降低了隐式迭代求解的收敛速度. 为此,本文使用隐式差分的多重网格算法进行弹 性波数值模拟,多重网格算法通过粗网格收敛较快的迭代过程求出近似解,以近似解为初值 使用细网格进行精确的迭代求解,从而加速了隐式迭代求解的过程,能够以较高计算速度、 精度、稳定性完成弹性波传播过程的数值模拟.     

Cylindrical-wave approach for the electromagnetic scattering problem by buried two-dimensional objects

A spectral-domain method, for the solution of the two-dimensional electromagnetic plane-wave scattering by a finite set of perfectly-conducting or dielectric cylinders buried in a dielectric half-space, has been developed. The scattered field is represented in terms of a superposition of cylindrical waves, and use is made of the plane-wave spectrum to take into account the reflection and transmission of such waves by the interface. The problem is solved for both the near- and the far-field regions, for TM and TE polarizations. In this work we briefly resume the theoretical basis of our approach. For configurations in which more obstacles are buried in the ground, and they are near to one another, we give details about the convergence rate of our method, and about the properties of our algorithms for the integration of cylindrical functions. With our technique it is possible to simulate two-dimensional buried obstacles of general shape, by means of a suitable set of circular-section cylinders: in this paper we show preliminary results of simulations carried out using arrays of same-radius circular cylinders, and of different-radius circular cylinders.